As you join CubeCraft you can see if your friends are connected with the /friends list command, however you can't go to them or even know where they are. That's why there should be a way to Teleport to your friends with a command. It would be easy then to find them. It would be useful also to go to them faster if you are chating with them. It wouldn't be necessary to wait for them to accept your TP, as they are your friends you should TP to them instantly. That's why a TP System would make easer and faster to find or go to your friends. If the friend you want to tp is in game you would tp to the lobby where he joined the game or you could tp to his game as an espectator.